Depth perception for a three dimensional (3D) TV is provided by capturing two views, one for the left eye and other for the right eye. These two views are compressed and sent over various networks or stored on storage media. A decoder decodes the two views and sends the decoded video to the 3D TV for display. The two views are known to be either merged into a single video frame or kept separate. When kept separate, the two views are known to be compressed and distributed using various methods. Two of these methods are multi-view coding (MVC) method and simulcast method. In the MVC method, the two views are compressed such that a correlation between the two views is exploited to increase coding efficiency. In the simulcast method, the two views are known to be compressed and distributed as two independent video streams.
MPEG standards (such as advanced video coding (AVC) or H.264 MPEG-4 and MPEG-2 systems) provide methods and syntax to represent and compress more than one view as well as to transport this compressed data in various ways. However, the current versions of the MPEG standards do not specify how to simulcast two views so that the two views can be decoded and combined appropriately to provide a 3D display. Consequently, simulcasting may not be currently done using MPEG standards for video systems and other types of systems.
Further, many broadcast centric standards (i.e. Society of Cable Telecommunications Engineers (SCTE) and Advanced Televisions Systems Committee (ATSC)) that are followed by a wide range of service providers and manufacturers do not allow sending two video components compressed with a same coding method within a same program or channel (i.e., two video components with the same “stream type” are not allowed in a program map table). This constraint precludes simulcasting of two video streams corresponding to the two eye views using a same compression standard in a same program. For example, the constraint precludes simulcasting two independent MPEG-2 or MPEG-4 streams (i.e. one for the left eye and one for the right eye for 3D TV) in the same program. Sending the two views in separate programs may be possible but adds complexity of requiring an additional tuner and time base synchronization between the two programs.
Furthermore, in many current proposals being discussed in MPEG and in the industry, both eye views are compressed using the same encoding standard. Because there are two dominant encoding standards, MPEG-2 and MPEG-4, this creates a backward compatibility problem for simulcast methods in digital TV systems that have mixture of MPEG-2 and MPEG-4 decoders. For instance, the MPEG-2 decoders will not be able to decode either view if the two views are compressed using the MPEG-4 standard.